Radiological image interpretation apparatus and method

ABSTRACT

A Radiology Healthcare Network provides high quality, timely medical interpretations of radiological images on a national (e.g., across the U.S.) and regional basis. The images can include images created by conventional x-ray technology, computed radiography, magnetic resonance imaging (MRI), computed tomography (CT), ultrasound imaging, nuclear medicine, and mammography equipment. The invention includes the acquisition of these images from health care facilities, the conversion of these images to digital format, the routing of these converted images, the interpretation of these routed images, and the routing of the interpretations back to the originating facility. The images are routed-(e.g., on a variety of high-speed digital and analog telecommunication networks) to the appropriate interpretation resource by an administrative site on the Network based on one or more requirements associated with the radiological study. The interpretation can be performed on high-resolution workstations and/or on films produced by film printers. The invention can include quality control measures which assure high image and interpretation quality. The control and tracking of images by the administrative site results in the production of a complete, signed interpretive report in a timely manner.

This is a continuation of Ser. No. 08/158,140 filed on Nov. 26, 1993.

BACKGROUND OF THE INVENTION

This invention relates to methods and apparatus for providingprofessional radiology interpretation services at locations distant fromthe healthcare facilities originating the studies in a centrallycontrolled and directed manner that results in the required kind ofradiology service (i.e., specialty or sub-specialty radiology asnecessary) delivered in a clinically effective and timely manner.

Conventional radiology services are traditionally site-based, where thehealthcare facility exclusively has radiology services provided to it byan on-site radiologist or radiology group. The on-site provider ofradiology services, depending on the size, kind, or location of thefacility, may or may not provide the desired breadth of radiologyservices over the desired timeframe. For example, small, rural hospitalstypically receive radiology service infrequently, by a circuit-ridingradiologist responsible for covering a plurality of healthcarefacilities. Another example of unmatched supply and demand for radiologyservices could be a non-hospital based diagnostic imaging center, wherea relatively low volume of studies oftentimes makes it difficult toattract the desired or necessary specialty or sub-specialty radiologyservices to the diagnostic imaging center.

In view of the foregoing, it is desirable to provide a system forimproving the distribution of radiology services which would result inan integrated regional and national system for standardized, centrallymanaged radiology services, available to all areas and types ofhospitals, thereby achieving efficiency and utilization of radiologistswith specialty and sub-specialty training and skills, resulting inimprovements in quality and controlling costs associated with providingradiology services.

SUMMARY OF THE INVENTION

This invention provides a Radiology Healthcare Network for providinggeneralist, specialty, and sub-specialty, timely medical interpretationsof radiological images on a national (e.g., across the U.S.) andregional basis. The images can include images created by conventionalx-ray technology, computed radiography, magnetic resonance imaging(MRI), computed tomography (CT), ultrasound imaging, nuclear medicine,and mammography equipment. The invention includes the acquisition ofthese images from healthcare facilities, the conversion of these imagesto digital format, the routing of these converted images, theinterpretation of these routed images, and the routing of theinterpretations back to the originating facility. The images are routed(e.g., on a variety of digital and analog telecommunication networks) tothe appropriate interpretation resource by an administrative site on theNetwork based on one or more requirements associated with theradiological study. The interpretation can be performed on workstationswith medical image grade monitors, and/or on radiographic films producedby laser camera based printers. The invention can include qualitycontrol measures which assure high image and interpretation quality. Thecontrol and tracking of images by the administrative site results in theproduction of a complete, signed interpretive report on a timely basis.

In general, the invention relates to a method for providinginterpretation of radiological images, which comprises providing anadministrative site coupled to a wide area network; providing aplurality of acquiring sites coupled to the wide area network fordigitizing radiological images and generating identifying informationabout a radiology study, the study including one or more of the images;providing a plurality of interpretation sites coupled to the wide areanetwork which each includes interpretation resources; and utilizing theadministrative site as follows. The administrative site receivesidentifying information about the study from one of the acquiring sitesover the wide area network; determines one or more study parameters fromthe received study identifying information; matches the study parametersto the interpretation resources available from the interpretation sitesto select one of the interpretation sites as an appropriateinterpretation site to interpret the study; routes the one or moredigitized radiological images onto the wide area network to the selectedinterpretation site; receives report information about an interpretationof the study from the selected interpretation site over the wide areanetwork; and routes the report information to the acquiring site fromwhich the study identifying information about the radiology study wasreceived.

Embodiments of the invention can include the following features:

The step of determining the one or more study routing parameters caninclude determining a modality of the study such as computer assistedtomography, conventional x-ray imaging, computed radiography, magneticresonance imaging, nuclear medicine, and ultrasound imaging; determininga pathology of the study, a geographic location of the acquiring site,information about a patient which is a subject of the study such aspatient age and sex, or information about an anatomy of a patient whichis a subject of the study; determining the requisite interpretationturnaround timeliness. The step of determining the suitable radiologyresources on the Radiology Healthcare Network. The step of best matchingan originated study with the best available radiology resource,according to routing parameters. The step of monitoring workflow in andout of radiology resources to ensure quality and timeliness of studyinterpretations.

Thus, the systems and methods according to the invention advantageouslymake high quality radiology interpretation services available to allareas uniformly and on an as-needed basis. Also, the invention utilizesa matrixed approach to providing radiology services which allowsefficient utilization of radiological expertise and thus controls coststypically associated with providing high quality and highly specializedradiology services.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram of an area communications system for providinginterpretation of radiological images to remote locations according tothe invention.

FIGS. 2A-2C are diagrams of another system for providing interpretationof radiological images to remote locations according to the invention.

FIG. 3 is a block diagram illustrating the flow of radiological studiesand interpretations controlled by an administrative site.

DESCRIPTION

Referring to FIG. 1, in accordance with this invention, a RadiologyHealthcare Network 10 for providing high quality generalist, specialty,and sub-specialty and timely medical interpretations of radiologicalimages on a national or regional basis includes a plurality of acquiringsites 12, 16, 18, 20, 22 and 24 for acquiring radiological images andrequesting radiological studies of those images, one or more radiologyhubs 26, 28 for providing general and specialty radiologicalinterpretation, one or more Strategic Radiology Partners (SRPs) 14, 32for providing highly specialized (sub-specialty) radiologicalinterpretation, and one or more network administration sites ("Admin.Sites") 30 for managing and controlling the flow and quality of imagesand interpretations across the Radiological Healthcare Network 10(hereinafter also referred to as the "Network").

In the disclosed embodiment, the acquiring sites can be primary carehospitals 12, 16, 18, 20, 22, 24, or other health service providerfacilities such as radiologic imaging centers, individual clinics anddoctor's offices, and mobile imaging services (herein collectivelyreferred to as "acquiring sites" for simplicity).

In the disclosed embodiment, the acquiring sites transfer the acquiredradiological images as studies (the "Study") typically consisting ofmultiple radiological images to the Radiology Healthcare Network 10 forinterpretation. The Radiology Healthcare Network consists of (i) atiered level of radiology healthcare providers who provide radiologyinterpretive services connected by specialized computer equipment andcomponents designed to support medical radiologic imaging, commonlyreferred to as either Picture Archive Communications Systems ("PACS") or"Teleradiology," and (ii) a wide area digital telecommunications networkprovided by existing (Local Exchange Carriers (LEC) and Inter ExchangeCarriers (IEC). The Study is routed by an Admin. Site 30 based upon thespecific requirements of the Study matched against the currentavailability of requisite expertise from radiology healthcare providerson the Network. The Admin. Site 30 can be a single central entity, or itcan be distributed among several entities on the network, determined by,for instance, workload, and redundancy for disaster recovery. Theprogress of the Study is monitored by the Admin. Site 30, and if notcompleted within certain pre-defined time-frames, the Study is re-routedby the Admin. Site to another Network radiology healthcare provider whois able to match the requirements of the Study.

Routing of Studies by the Admin. Site 30 is based upon the specificinterpretive needs of the Study, such as the availability of therequisite specialty or sub-specialty radiologic staff to interpret theStudy, all with a potential preference for the closest radiologyhealthcare provider within a specific geographic area. Specifically,Study parameters which can effect Study routing include patientdemographics (e.g., age and sex), suspected pathology, imaging modality,imaged body part(s), required turnaround time of the interpretation,geography, and Study type (e.g., routine diagnostic interpretation, statinterpretation, quality assurance interpretation, overreadinterpretation).

Referring to FIG. 3, the flow of operational control of a patientradiologic Study is shown. As an initial step in the flow, an acquiringsite such as a hospital 100 acquires digital representations of one ormore radiological images which together form a patient radiologic Study(the "Study"). The Study typically has other information associatedtherewith such as the suspected pathology, the modality, the anatomy,patient-identifying data, location of the acquiring site. The associatedStudy information also might include the level of urgency of the Study,and other Study parameters. The associated Study information (andpossibly the image data itself) is then transmitted (as indicated byarrow 102) to an Admin. Site 104. In general, the Admin. Site 104 storesall of the patient information and Study images which is transmitted toit, for example, by using storage devices capable of storing largeamounts of data such as redundant arrays of independent disks (RAID)and/or optical disk jukeboxes.

After the Admin. Site 104 receives the transmission from the hospital100, the Admin. Site 104 determines a set of Study parameters, from theassociated Study information, which characterize the Study. The Admin.Site then checks the Study parameters against (as indicated by arrow112) the resources of available Network interpretation sites, such asregional radiology hubs and/or strategic radiology partners (SRPs) inthe Radiology Healthcare Network, for the best resource available forthat Study. In the embodiment of FIG. 3, the interpretation sitesinclude one regional radiology hub 106 and two SRPs 108, 110 which arecoupled to the Admin. Site 104. This check by the Admin. Site 104 caninclude a check on (i) the availability of medical generalists,specialists, and sub-specialists, (ii) the types of such availablemedical personnel and their hours of coverage, and (iii) the existingbacklog at the hub and/or SRPs. The backlog refers to the number ofStudies and/or related information which already have been sent to thehub or SRP and which have yet to be acted on by the hub or SRP. Theinformation which the Admin. Site 104 gathers as a result of thesechecks is then used to determine how to route the Study from theacquiring site for interpretation.

Having made the routing determination, the Admin. Site 104 routes theStudy to an electronic reading stack at the appropriate radiology hub106 or SRP 108, 110 as indicated by arrow 114. The Admin. Site canaccomplish this routing without having to actually receive the Studyitself. Rather, it can direct the Network to make the appropriateconnection between the acquiring site and the selected hub or SRP sothat the images can be transferred directly.

The Admin. Site 104 then periodically monitors the progress being madeon the Study that was routed to the radiology hub or SRP to determinewhether the hub or SRP is interpreting the Study in a timely manner (asindicated by arrow 116). If the interpretation is not completed within apredetermined amount of time, the Admin. Site 104 can (i) delete theStudy from the electronic reading stack of the radiology hub or SRP towhich that Study was routed and then (ii) re-route that Study to a newinterpretation site (e.g., radiology hub or SRP).

After the Study reaches a hub or SRP capable of rendering the necessaryinterpretation services in a timely manner, that hub or SRP interpretsthe Study and notifies the Admin. Site 104 of the existence of aninterpretive report of the Study (as indicated by arrow 118). The Admin.Site 104 then can either receive the interpretation directly and routeit back to the hospital 100 which acquired the Study initially or it canroute the interpretation from the interpreting site to the hospitaldirectly. The Admin. Site 104 can also receive and store a copy of thereport.

Note that the interpretation site, whether it is a radiology hub or anSRP, which receives the Study in its electronic reading stack as routedby the Admin. Site 104 might not complete an interpretation of the Studyfor a variety of reasons. Those reasons can include (i) the fact thatthe Study was not received by the interpretation site with satisfactoryquality; (ii) the interpretation site needs more information to completean interpretation; or (iii) the interpretation site requires moremedical expertise than is available thereat. In these situations, theinterpretation site typically will (i) request a re-transmission of theStudy from the Admin. Site 104; (ii) request the Admin. Site 104 torequest more images and/or Studies from the hospital 100 which initiallysent the Study; or (iii) request the Admin. Site 104 to delete the Studyfrom its electronic reading stack and then route that Study to anotherinterpretation site that has the needed expertise.

Radiology healthcare providers who provide radiology interpretiveservices on the Network are tiered according to the type of generalist,specialty, and sub-specialty expertise available within the institution,the number of staff within a specific expertise in the institution, andtheir hours of coverage.

A regional radiology hub can typically provide radiology interpretationservices that are otherwise unavailable at the acquiring site, and maybe a general referral site for the acquiring site, e.g., the radiologyhub may be a university hospital or regional health care facility thatmay normally gets referrals from the acquiring site hospital. Theradiological services provided by a radiology hub typically includesbasic radiologic interpretation, specialty interpretation, urgentinterpretation, and interpretation services at extended hours ofcoverage. With such a system, there does not need to be a radiologistpresent at the acquiring site, rather only a radiology techniciancapable of producing a satisfactory radiology image.

An SRP is typically a major radiology center which offers radiologyservices usually unavailable at the radiology hubs, such assub-specialization, urgent interpretation, quality assuranceinterpretation, consultations, and expanded hours of coverage. SRPs caninclude larger, well-known medical centers, such as the Brigham & WomensHospital and The Cedar Sinai Medical Center, which offer high levelexpertise and sub-specialty availability. In general, the SRPs have ahigher level of radiological image interpretation sub-specialtyexpertise, more advanced radiological facilities, and higheravailability than the radiology hubs. Like the radiology hubs, the SRPsinterpret the radiology Study and produce reports which are directedback to the appropriate acquiring site.

Hospitals, radiology hubs, SRPs, and Admin. Sites are interconnectedthrough a flexible high speed digital data communications network whichutilizes as its backbone an existing and future contemplated, InterExchange Carrier (IEC) packet and cell switched wide area network 34(WAN). It may also be possible, with acceptable compression techniquesto use voice grade switched of dedicated lines to replace both the LECand IEC portions of the Network.

In general, the WAN 34 can use "frame relay" which combines theperformance of private telephone lines with the bandwidth efficiency andsuperior connectivity of packet switching. In short, frame relay is anadvanced, packet data communications technology designed for bursty,data-intensive applications such as image transfer and client/serverexchange. The WAN 34 frame relay services typically are provided by longdistance carriers such as AT&T, Sprint or MCI.

Acquiring sites can be connected to an associated radiology hub througha direct high speed point-to-point connection established through aLocal Exchange Carrier (LEC), such as NYNEX, or through a combination ofconnections through the radiology hubs and the WAN using both IEC andLEC channels. It may also be possible to use cable television networkservices to provide LEC and IEC network services. The flexibility ofthese numerous connection strategies allows for connections to beoptimized based on tariffs, connection, and equipment costs, andprovides a seamless network to allow for the routing of Studies on anational basis.

For example, in FIG. 2A, Hospital A 62 is an acquisition site having aregional affiliation with Radiology Hub 1 72, and may opt for apoint-to-point or multiplexed point-to-point connection 63 directly withRadiology Hub A, established via an intralata connection to a LEC.

In another example, Hospital C 68 may also have an affiliation withRadiology Hub 1 72, but may find that a direct point-to-point connectionto Radiology Hub 1 through an LEC to be prohibitively expensive due tointerlata tariffs, connection, or equipment costs. In this case it maybe more cost effective for Hospital C to establish a direct link 75 withthe IEC WAN 34 and connect to Radiology Hub A through the packet/cellswitched network WAN 34 and connection 73 between Radiology Hub 1 andWAN 34.

The use of point-to-point LEC and packet and cell switched IEC digitalcommunications circuits as described above, provides for a highlyflexible radiology interpretation network architecture in whichradiology images can be routed quickly, easily, and economically betweenany acquiring sites, radiology hubs, SRPs and Admin. Sites. Thisprovides for an economically viable method of transmitting medicalimages (which are large in size) on a regional and national basis in atotally seamless way directed by a central (single or multipoint) Admin.Site.

At the interpretation sites, board-certified radiologists interpret thetransmitted Studies by, for example, using workstations to view theimages. The workstations generally utilize state-of-the-art technologyand reproduce images at a resolution appropriate for making finalinterpretations, or alternatively the images may be printed by a lasercamera film printer. If the radiologists need additional information,the Admin. Site will then contact the transmitting site (e.g., bytelephone or electronic mail). Conference calling capabilities are alsoavailable.

After making an interpretation, the radiologist typically dictates areport of findings, has the dictation transcribed, reviews thetranscribed report, and then signs the report, all coordinated by theAdmin. Site. The report is then sent back across the Network to theacquiring site (e.g., by facsimile,remote print services, or electronicmail) and treated as any other medical test result by the medical recordhandling system at the acquiring site. A hardcopy of the report also maybe sent by mail for confirmation.

In the disclosed embodiment, the acquiring sites produce digital datarepresentative of radiological images, and the transferring of thedigital data within the system 10 is performed by digital transmission.The long distance digital transmission of images, such as those betweenthe radiology hubs and the SRPs, are performed using standard digitalpacket and cell switched WAN common carrier services. In FIG. 1, WAN 34performing these services is represented by a cloud and can be anydigital WAN common carrier service such as that offered by long distancecarriers AT&T, SPRINT and MCI.

Throughout the system 10, the digital transmission is done with framesor packets or cells. That is, in general, all digital bits whichrepresent an image are not sent at one time. Instead, the bits arebroken into discrete portions (frames or packets), and these portionsare sent separately to the receiver which reassembles them upon receipt.The particulars of the digital communication links which can be utilizedin the system 10 are described below with reference to FIGS. 2A-2C.

In packet switching, a message is divided into packets which typicallycontain many bits each, and the message is transmitted packet-by-packet.Packet and cell switching all conform to one of four standard protocols:X.25; Frame Relay; SONET; and ATM. The appropriate standards for theseprotocols are known to those skilled in the art.

Digitization of a typical radiological hardcopy image (e.g., aconventional 14 inch by 17 inch x-ray film) results in approximately 10Mbytes (i.e., 80 Mbits) of data, and in general, studies range in sizefrom a few megabytes for ultrasound and nuclear medicine, to more than100 megabytes for direct capture digital MR Studies. Thus, datagenerated is substantial for each Study that must be transferred acrossthe network in a timely, cost efficient, and seamless manner.

Having generally described a system according to the invention, a moredetailed description of the variety of possible communication links (andcorresponding electronic hardware) which can be utilized in systemsaccording to the invention will now be provided.

Systems according to the invention can use various digital communicationlinks for transferring radiologic Studies among acquisition sites (e.g.,the hospitals), radiology hubs, SRPs, and Admin. Sites. The digitallinks can include (i) T1/DS-1 carrier point-to-point services whichoperate at 1.544 Mbits/sec, (ii) DS-0 digital services which operate at64 kbits/sec, (iii) DS-3 digital services which operate at 44,736Mbits/sec, (iv) ATM and SONET links which operate at between 56Mbits/sec and 2 Gbits/sec (v) Frame Relay links that operate at between9,600 and 1,544,000 bits/sec., (vi) Ethernet or 802.3 LAN links whichoperate at 10 Mbits/sec, (vii) IEEE 802.6 standard metropolitan areanetworks (MANs), and (viii) ISDN (Integrated Services Digital Network)end-to-end services.

Systems according to the invention can use various software protocolsfor transferring medical images between the acquisition sites, regionalhubs, SRP's and other locations. One such protocol, although not limitedto this protocol, is referred to as TCP/IP (Telecommunications ControlProtocol/Internet Protocol). This protocol makes it possible to dividethe image into packets, and route these packets over a variety ofcommunications equipment and services, resulting in image transmissionwith complete end-to-end file integrity. Other protocols may includeNovel IPX, Appletalk, DECnet, or ISO.

Systems according to the invention can use networking equipment tophysically connect and transmit the TCP/IP packets over the variousnetwork services. This equipment is selected, integrated, configured(special parameter settings for high volume image transmissions must bemade), and managed by the Admin. Site. This equipment includes, but isnot limited to, Ethernet Controllers on general purpose computers,bridge/routers, CSU/DSU's, multiplexers, network hubs, FDDI controllersand cables and ATM controllers and cables.

Referring to FIG. 2A, in another embodiment of the invention, aRadiology Healthcare Network 60 according to the invention includesimage acquiring hospitals 62, 64, coupled to a regional radiology hub 72and another image acquiring hospital 68 coupled directly to a digitalpacket switched WAN 70. Other elements of the system 60 include SRPs 76,78 and another radiology hub 80.

As indicated, hospital 62 is coupled to radiology hub 72 by either a T1or DS-1LEC channel 63. Hospital 64 is coupled to radiology hub 72through four multiplexed DS-0 LEC channels 65, for a total availabledigital signaling rate of 256 kbit/sec. The multiplexed DS-0 channelsare demultiplexed by equipment at the radiology hub 72.

Imaging center 66, SRP 78, and radiology hub 80 are each coupled to anAdmin. Site 74 by either a T1 or DS-1LEC circuit 67, 69, and 71,respectively. Regional radiology hub 72, hospital 68 and SRP 76 are eachcoupled to the IEC WAN 70 over T1 or DS-1 channels 73, 75 and 77,respectively. The Admin. Site 74, which requires higher signaling ratesdue to the high image traffic expected to pass through the hub, canutilize multiple T1 or DS-1 channels 79, or a T3 or DS-3 channel, or ahigh data rate Asynchronous Transfer Mode (ATM) packet transmissiontechnology.

Note that while particular coupling configurations are shown in FIGS. 1and 2A, other configurations are possible which also result in systemscapable of acquiring radiological images and transferring them to one ormore distant sites for interpretation in accordance with the invention.However, irrespective of their physical network topology andcombinations of circuits used, it becomes both seamless and transparentas to how the images are logically routed through the network.

Referring to FIG. 2B, a more detailed diagram of a portion of FIG. 2Ashows image communication hardware included in hospitals 62, 64, 68 andradiology hub 72. The hospitals include image acquisition equipment 38coupled to a digital data router 82 via a local area network (LAN) 84which conforms to the IEEE 802.3 standard. Router 82 in turn isconnected to a WAN (or serial) interface which connects to T1 or DS-1channel 86 which is then physically connected to the T1/DS1 63.

Regardless of the technique used to acquire the digital datarepresentative of a radiological image, the digital data is thenconverted, by the image acquisition equipment 38, to, for example, anACR-NEMA (American College of Radiology, and National ElectricalManufacturers Association) digital radiology image file format. Ingeneral, all components of the system according to the invention mayadhere to the ACR-NEMA standard and are capable of manipulating (e.g.,creating, storing, sending, receiving, writing, and reading) data inthis format. That is, in the disclosed embodiment, the image acquisitionequipment 38, image storing and routing equipment 98, and the imageviewing equipment 96 can adhere to the ACR-NEMA standard. The ACR-NEMAstandard is a well-documented, flexible, and open digital imaging-andcommunication standard which is likely to become an internationalstandard for medical imaging. ACR/NEMA or DICOM is layered on top of theTCP/IP protocol suite. Other protocols, including proprietary vendorprotocols are included in this invention.

Specific imaging, computer hardware, software, and networking equipmentcan be deployed to support the system defined herein. Equipment at eachtype of site is defined (but not limited to) as follows:

Acquisition Site:

Acquisition equipment 38 is deployed depending upon the image modalityto be supported. For sites acquiring images from plain film, a filmdigitizer employing either laser or CCD technology is used to transferthe analog film data into an accurate digital representation of thedata. An example of a film digitizer is a LUMISYS, manufactured byLumisys, Sunnyvale, Calif. Digital film images are usually 10 Mbyteseach. The digital data is then usually transferred from the filmdigitizer to a host computer via a high-speed interface such as SCSI or84 IEEE 802.3. The host computer allows demographic input of patient andStudy data to be logically combined with the image data, and then uses anetwork protocol (such as TCP/IP and/or ACR/NEMA or DICOM) to transmitthe Study over the network. The image can be transferred from the 802.3controller on the acquisition computer on an IEEE 802.3 LAN to an IEEE802.3 port on a bridge/router 82. The bridge/router 82 then reformatsthe TCP/IP packet stream into the appropriate wide area protocol(examples are, but not limited to, HDLC, Point-To-Point or Frame Relay)and transmits the stream to the CSU/DSU 86, which then synchronizes andtransmits the stream to the appropriate circuit.

For acquisition sites supporting computed radiography, the chargedphosphor plate common to this modality is inserted into a computedradiography reading computer, which then converts the phosphor imageinto a digital representation. The image is transferred to a hostcomputer via a high-speed interference such as SCSI or 802.3. The hostcomputer allows demographic input of patient and Study data to belogically combined with the image data, and then uses a network protocol(such as TCP/IP and/or ACR/NEMA or DICOM) to transmit the Study over thenetwork. The image can be transferred from the IEEE 802.3 controller onthe acquisition computer on an IEEE 803.3 LAN to a IEEE 802.3 port on abridge/router 82. The bridge/router 82 then reformats the TCP/IP packetstream into the appropriate wide area protocol (examples are, but notlimited to, HDLC, Point-To-Point or Frame Relay) and transmits thestream to the CSU/DSU, which then transmits the stream to theappropriate circuit.

For those sites supporting MR, CT, ultrasound, and nuclear medicineimaging, one method of obtaining the images is via a video (or commonlyreferred to as "frame grabber") interface. These interfaces include acomputer acquisition board which has an input the video signal fromthese modalities. The board creates a digital representation of thevideo signal and stores it on the acquisition computer system. The hostcomputer allows demographic input of patient and Study data to belogically combined with the image data, and then uses a network protocol(such as TCP/IP and/or ACR/NEMA or DICOM) to transmit the Study over thenetwork. The image can be transferred from the IEEE 802.3 controller onthe acquisition computer on an IEEE 802.3 LAN to a IEEE 803.3 port on abridge/router 82. The bridge/router 82 then reformats the TCP/IP packetstream into the appropriate wide area protocol (examples are, but notlimited to, HDLC, Point-To-Point or Frame Relay) and transmits thestream to the CSU/DSU 86, which then transmits the stream to theappropriate circuit.

MR and CT scanners may also be connected in this system via directdigital interfaces. Direct digital interfaces move the images andpatient and demographic data from the scanner to the network, or toanother general purpose computer which may reformat the images intoanother organization of network protocol. The image can be transferredfrom the IEEE 803.3 controller on the acquisition computer on an IEEE802.3 LAN to a IEEE 802.3 port on a bridge/router 82. The bridge/router82 then reformats the TCP/IP packet stream into the appropriate widearea protocol (examples are, but not limited to, HDLC, Point-to-Point orFrame Relay) and transmits the stream to the CSU/DSU 86, which thentransmits the stream to the appropriate circuit.

Acquiring sites may have a dedicated T1/DS-1 63 connected to either aradiology hub 72 or directly to the packet/cell switched WAN via aT1/DS-1 75. In addition, based upon whether the acquiring location iswithin the same lata as the regional hub, and the network bandwidthrequirements are not significant (greater than 256k bits/second),multiple DS-0 65 circuits can be multiplexed together to form andpresent to the WAN port on the bridge/router 92 a single 256 bit/secondcircuit.

Regional Radiology Hub:

Equipment at a regional radiology hub 72 can include networkingcomponents 86, 88, 90, 92, 94, and cabling, high-resolution imageviewing workstations 96, laser camera based film printer digitizer, andperhaps a file server 98 (referred to as an Image Router).

Network components consist of a multiple WAN port bridge/router 92 witha LAN port supporting IEEE 802.3, or other higher speed LAN protocols.CSU/DSU's 86 will also be used to support each physical circuit. Forthose regional hubs with Hospitals connecting via multiplexed DS-0circuits 65, a network multiplexer 88 will be used.

Regional radiology hubs may be directly connected to the WAN 70 byeither a dedicated direct T1/DS-1, T3, DS-3, or ATM connection to theAdmin. Site, or by a T1/DS-1, TC/DS-3, or an ATM connection to the WideArea Packet/Cell switched network 73.

Most radiologic interpretations will be performed on high-resolutionimage viewing workstations 96. High resolution workstations consist of ageneral purpose computer (i.e. Macintosh, or IBM-PC Compatible, or RISCOmp) continuing at least a few hundred megabytes to a few Gbytes ofmagnetic storage, main memory, specialized graphics display boards, andfrom 1 to 8 high resolution grey-scale or color monitors. For example,suitable image viewing equipment includes equipment commerciallyavailable, but not limited to, Kodak Health Imaging Systems ofRichardson, Tex. such as the Personal Display System (PDS). Theworkstation 96 can be an Apple Quadra 950, Quadra 800, or Centris 650running MAC OS 7.x. The workstation can include a local hard diskhaving, for example, 230 Mbytes to 5.2 Gbytes capacity and video displaycard having, for example, 16 Mbytes of capacity. Monitors associatedwith the workstation can include 1.2 k by 1.6 k resolution displays with16-bit mapped to 8-bit via LUT (Loan Up Table) and having a 60 Hz scanrate and/or 2 k by 2.5 k resolution displays with 16-bit mapped to 8-bitvia LUT and having 65 Hz scan rate. Printers can include laser filmprinters such as the Kodak Ektascan Laser Printer Model 2180, the 3MLaser Imager Model P831, the 3M Laser Imager Plus Model M952, and theAgfa/Matrix Compact L Printer.

In addition, a regional radiology hub can support significant imagevolumes and be configured with a file server 98. A file server 98consists of a general purpose computer with sufficient magnetic and/oroptical storage usually from 1 to 20 Gbytes. A file server also consistsof a network operating system and application software to allow thetransparent routing of images from the WAN to the LAN.

SRP:

Equipment at an SRP can include network components and medical imaginghigh resolution image viewing workstations, laser camera based filmprinters, and perhaps a file server.

Network components consist of multiple wide area network portbridge/routers 86 with a LAN port supporting IEEE 802.3 or other higherspeed LAN protocols. CSU/DSU is well also be used to support eachphysical circuit.

SRP's may be directly connected to the WAN by either a dedicated directT1/DS-1, T3, DS-3, or ATM connection to the Admin. Site, or by aT1/DS-1, TC/DS3, or an ATM connection to the Wide Area Packet/Cellswitched network.

Most radiologic interpretations will be performed on high-resolutionimage viewing workstations. High resolution workstations consist of ageneral purpose computer (i.e. Macintosh, or IBM-PC Compatible, or RISCOmp) continuing at least a few hundred megabytes to a few Gbytes ofmagnetic storage, main memory, specialized graphics display boards, andfrom 1 to eight high resolution grey-scale or color monitors. Forexample, suitable image viewing equipment includes equipmentcommercially available but not limited to Kodak Health Imaging Systemsof Richardson, Tex. such as the Personal Display System (PDS). Theworkstation 58 can be an Apple Quadra 950, Quadra 800, or Centris 650running MAC OS 7.x. The workstation can include a local hard diskhaving, for example, 230 Mbytes to 5.2 Gbytes capacity and video displaycard, having, for example, 16 Mbytes of capacity. Monitors associatedwith the workstation can include 1.2 k by 1.6 k resolution displays with16-bit mapped to 8-bit via LUT (Loan Up Table) and having a 60 Hz scanrate and/or 2 k by 2.5 k resolution displays with 16-bit mapped to 8-bitvia LUT and having 65 Hz scan rate. Printers can include laser filmprinters such as the Kodak Ektascan Laser Printer Model 2180, the 3MLaser Imager Model P831, the 3M Laser Imager Plus Model M952, and theAgfa/Matrix Compact L Printer.

In addition, an SRP can support significant image volumes and beconfigured with a file server. A file server consists of a generalpurpose computer with sufficient magnetic and/or optical storage usuallyfrom one to 20 Gbytes. A file server also consists of a networkoperating system and application software to allow the transparentrouting of images from the WAN to the LAN.

Admin. Site:

The Equipment at the Admin. Site 74 consists of network circuits,networking components and cabling, file server(s), RAID and/or opticalstorage devices, PACS or Teleradiology software, an administrativedatabase computer 117, and a Study tracking mechanism.

Circuits to the WAN include single T1/DS-1, multiple T1/DS-1, T3/DS-3,or ATM connections 79 to the IEC packet/cell switched network, and anyadditional of the aforementioned circuits required to accomplish directwide area connections to either SRP's, radiology hub's, or otheracquiring hospitals.

Networking equipment consists of high speed bridge/routing hubs 100 (forexample, the Cisco 7000, manufactured by Cisco Systems, Menlo Park,Calif.) which provide backbone bandwidth in aggregate of 500Mbits/second. This bridge/router 100 has multiple WAN ports capable ofhandling wide area connection circuits of varying speeds. Thebridge/router 100 also has a LAN connection 106 to a high-speed backbone110 supporting either IEEE 803.3, the proposed "Fast Ethernet" protocol,FDDI, and/or ATM, although other high-speed LAN technologies could alsobe used as they are developed. Of course, each separate physical widearea circuit needs the appropriate CSU/DSU 86, 102, 104 or other modem.

Connected to the high speed LAN 110 is a file (image) server(s) 112 withattached RAID device 114 to allow high throughput file read/writeoperations (from 4 to 100 megabytes/sec.), and/or optical storagedevices to allow permanent archiving of medical images. Optical tapeunits could also be used.

PACS or Teleradiology software, provided by existing vendors, allows forthe routing of images to either radiology hubs or SRP's. This softwareoperates at a layer above the network protocol, although it is possiblefor the network protocol (e.g., the TCP/IP suites as Networked FileServer of the File Transfer Protocol, or Novel IPX/SPX) to allow theimages to be distributed without any additional PACS or Teleradiologysoftware used.

The administrative database computer 117 can be use to manage theradiology resources on the Network and be used to make many of the Studyrouting decisions based on the Study parameters and the availableresources. A tracking mechanism, either electronically based or manuallybased can be used to track and monitor the progression of Studies on thenetwork. In addition, an Admin. Site may also have high resolution imagestations.

The following more specifically, describes various equipment used inacquiring sites, hubs, and SRPs. The image storage and routing equipmentcan include an image server 112 (Admin. Site 74 of FIG. 2C) having oneor more storage units 114. The storage units 114 can include magneticand/or optical disks. Suitable image storage and routing equipmentincludes equipment commercially available from a variety of vendors.Such vendors may include (but are not limited to) Kodak Health ImageServices ("KHIS"), AVP/E-Systems, Images On-Call or Radman. The KHISequipment can include a SUN workstation running, for example, SUN OS4.1.x or SUN Solaris 1.x or 2.x and the DBMS database management toolfrom Sybase. The Kodak equipment can include the Ektascan Model 6800Automated Disk Library which uses 14 inch optical disks, the Model 560Automated Disk Library which uses 5.25 inch optical disks, thestandalone 14 inch optical disk drive, and the stand-alone 5.25 inchoptical disk drive. The optical disk units can be "jukeboxes" whichtypically provide at least about 1 terabyte storage capacity (where terais the prefix for 1 X 10¹²). The storage units also can include RAID(Redundant Arrays of Inexpensive Disks) technology. The SUN workstationcan be interfaced with the storage units via a Small Computer SerialInterface (SCSI) port. Data compression may or may not be used in thestorage of data.

The image viewing equipment 116 can include a reading workstationcapable of displaying gray scale or color radiological images on a CRTdisplay, and/or printing hardcopies of the radiological images that areacquired and sent by the image acquisition equipment 38 and/or that arestored, retrieved, and sent by the image server 112. In general,suitable image acquisition equipment 38, image server 112, and imageviewing equipment 116 is commercially available from multiple vendorsincluding Vortech Data, Inc. of Richardson, Tex. and Eastman KodakCompany of Rochester, N.Y. under the product name Imagelink.

Each radiological image acquiring site includes at least imageacquisition equipment 38. The acquiring sites (e.g., the hospitals)typically also include an image server 112 and/or image viewingequipment 116. At a minimum, the interpreting sites (e.g., the hubs andthe SRPs) include the image viewing equipment 116, but they typicallyalso include the image acquisition equipment 38 and/or the image server112.

Acquisition of a digital data representative of a radiological image canbe accomplished by the image acquisition equipment 38 in a variety ofways. For example, radiographic film (i.e., an x-ray image on film) canbe converted to a digital image (digitized) using a film digitizer. Thefilm digitizer can be controlled by a computer workstation such as a SUNSPARC or a SUN IPC, available from SUN Microsystems. Workstations can beused to manipulate, format, store, and transmit the digitized imageoutput from the film digitizer, i.e., act as an intelligent interfacebetween the digitizer and the radiology network. While a variety ofconfigurations for the workstation are possible, the workstation, if aSUN IPC, can be configured with an 876 Mbyte hard disk and 36 Mbytes ofinternal random access memory (RAM). The SUN IPC can run the SUNoperating system (OS) 4.1.x or the SUN Solaris 1.x or 2.x. The filmdigitizer 44 can be a Lumiscan (model 150 or model 200) which isavailable from Lumisys of Sunnyvale, Calif.

Another technique for acquiring the digital data is by directlycapturing and digitizing video images (without first reducing them tohardcopy) from the image acquiring equipment. Video imagecapture/digitization is useful with computed tomography (CT), magneticresonance imaging (MRI), nuclear medicine, and ultrasound imagingbecause each of these techniques produces video images as a standardoutput format. Commercially available "frame grabbing" electronics canbe used to capture and digitize the video images. In general, theframe-grabbing electronics are contained in or coupled to a hostcomputer platform 50 such as a SUN platform. A typical configuration forthe platform includes local storage capacities of from about 0.5 Gbytesto 6 Gbytes. The platform can run the SUN OS 4.1.x or the SUN Solaris1.x or 2.x. The frame-grabbing electronics can have 8-bit or 12-bitdigital capture capability.

As another example, some image acquiring equipment provide digitalrepresentations that can be accessed directly (i.e., without firstcreating a hardcopy or a video image and then digitizing the hardcopy orvideo image) by commercially available hardware. Such digitalrepresentations of an acquired image are typically presented after theacquiring system has performed post-processing on the acquired image,and is presented in a standard digital radiological image format.

The routers 82 and 92 of FIG. 2B and the router 100 of FIG. 2C can becommercially available routers from, for example, Cisco Systems, Inc. ofMenlo Park, Calif.

Other modifications and implementations will occur to those skilled inthe art without departing from the spirit and the scope of the inventionas claimed. Accordingly, the invention is to be defined not by thepreceding illustrative description, but by the following claims.

What is claimed is:
 1. A method for interpreting radiological images,comprising:a) generating a radiological image at an image acquiringsite; b) creating a radiology study which includes the image andidentifying information about the study; c) digitally transmitting theidentifying information about the study over a wide area network to adigital processing system at an administrative site for determination ofradiological study parameters from the identifying information, andselection of an interpretation site based on the study parameters andinformation stored at the administrative site relating to each of aplurality of interpretation sites; d) digitally transmitting the studyover a wide area network to an interpretation site in response to acommand signal from the administrative site; and e) receiving aninterpretation of the study at a site determined by the administrativesite.
 2. The method of claim 1, wherein the study first is transmittedfrom the acquiring site to the administrative site in response to thecommand signal.
 3. The method of claim 2, wherein the study istransmitted from the administrative site to the interpretation site. 4.The method of claim 1, wherein the study is transmitted from theacquiring site directly to the interpretation site in response to thecommand signal.
 5. The method of claim 1, wherein the identifyinginformation includes patient information such as age, sex, or otherdemographic information, suspected pathology, modality, anatomy andlocation of the site where the radiological image acquisition wasperformed.
 6. The method of claim 1, wherein the information relating tothe interpretation sites includes information relating to theavailability of medical providers, their hours of coverage, and theexisting backlog at the interpretation site.
 7. The method of claim 1,wherein the administrative site monitors the progress of theinterpretation of the study by the interpretation site.
 8. The method ofclaim 7, wherein the administrative site monitors the interpretationsite for timeliness.
 9. The method of claim 7, wherein theadministrative site monitors the interpretation site for requests foradditional images or identifying information.
 10. The method of claim 1,wherein the administrative site monitors the time during which theinterpretation site is generating an interpretation of the study, and ifthe time monitored is greater than a predetermined time allotted forinterpretation, the study is transmitted to a different interpretationsite.
 11. A method for interpreting radiological images comprising:a)providing a digital processing system for use at an acquiring site for:(i) generating a study containing one or more radiological images, (ii)generating identifying information about the study, and (iii)transmitting the study and the identifying information over a wide areanetwork; b) providing a digital processing system for use at anadministrative site for: (i) receiving the study and identifyinginformation over the wide area network, (ii) storing informationrelating to a plurality of image interpretation sites which are coupledto the wide area network, (iii) performing a comparison between theidentifying information and the information relating to the imageinterpretation sites, (iv) using the comparison to select an imageinterpretation site, and (v) controlling the routing of the study to theinterpretation site over the wide area network; and c) providing adigital processing system at an image interpretation site for: (i)receiving a study over the wide area network, (ii) displaying the studyon a high-resolution image viewing system, (iii) generating a reportrelating to the study and (iv) transmitting the report over the widearea network to a site determined by the administrative site.
 12. Themethod of claim 11, further comprising prompting a user at the acquiringsite to enter identifying information relating to patient and studydemographics such as age, sex, other demographic information, suspectedpathology, modality, anatomy and the location of the acquiring sitewhere the radiological image acquisition was performed.
 13. The methodof claim 12, wherein the administrative site prompts the acquiring siteto initiate transfer of the study to the administrative site.
 14. Themethod of claim 12, wherein the administrative site prompts theacquiring site to initiate transfer of the study to the interpretationsite.
 15. The method of claim 11, wherein the information relating tothe plurality of interpretation sites comprises information about theavailability of medical providers, hours of their coverage, and existingbacklog at the site.
 16. The method of claim 11, further comprisingprompting a user at the interpretation site to enter data relating to aninterpretation of the study.
 17. The method of claim 11, wherein thedigital processing system for use at the administrative site monitorsthe generation of the report at the interpretation site for timeliness.18. The method of claim 17, wherein the digital processing systemtransmits the study to a different interpretation site when generationof the report appears untimely.
 19. The method of claim 17, wherein thedigital processing system monitors the interpretation site for requestsfor additional images or information.
 20. A method for providinginterpretation of radiological images, comprising: using a wide areanetwork to communicate between: (i) a data processing system located atan administrative site, (ii) digital transmission equipment located at aplurality of image acquiring sites for transmitting onto the wide areanetwork digital radiological images and identifying information relatingto a study performed at the acquiring site, and (iii) digital receivingequipment located at a plurality of image interpretation sites forreceiving the digital radiological images and identifying information;wherein the data processing system at the administrative site receivesidentifying information about a study from one of the acquiring sites,determines study parameters from the identifying information, comparesthe study parameters with information stored at the administrative siterelating to the plurality of image interpretation sites, selects aninterpretation site for interpretation of the study, and controls therouting of the study from the acquiring site to the interpretation sitefor interpretation of the study; and wherein the interpretation sitegenerates a report about the study and transmits the report over thewide area network to the acquiring site that generated the study.
 21. Asystem for providing interpretation of radiological images,comprising:at least one image-acquiring site comprising: (i) acquisitionequipment for obtaining images, (ii) a host computer for creating astudy comprising patient information and the images, (iii) networkingequipment for routing the study over a wide area network; anadministrative site coupled to at least one image acquiring site by awide area network, comprising: (i) a data processing system for:receiving the study, selecting an interpretation site based on adetermination of radiological parameters from the patient information,initiating transmission of the study to the selected interpretationsite, and monitoring the progress of an interpretation at theinterpretation site, and (ii) networking equipment for transmitting thestudy to a selected interpretation site; and at least one interpretationsite coupled to the administrative site by a wide area network,comprising: (i) a high-resolution image viewing workstation for viewingthe study, (ii) a computer for generating an interpretation of thestudy, and (iii) networking equipment for routing the interpretationunder the control of the administrative site.
 22. A method forinterpreting radiological images, comprising:(a) generating aradiological image at an image-acquiring site; (b) creating aradiological study which includes the image and identifying informationabout the study; (c) at an administrative site coupled with theimage-acquiring site, selecting an interpretation site based on studyparameters and information stored at the administrative site; (d)digitally transmitting the study over a wide area network to aninterpretation site in response to a command signal from theadministrative site; and (e) receiving an interpretation of the study ata site determined by the administrative site.